Thesis
Drilling of carbon fiber reinforced plastics/titanium stacks with ultra hard coated carbide tools
Washington State University
Master of Science (MS), Washington State University
2013
Handle:
https://hdl.handle.net/2376/106332
Abstract
Carbon fiber reinforced plastics (CFRP) have become increasingly popular materials for many industries because of their high strength to weight ratio. In aerospace applications hybrid composite materials are often used in constructing structures. Hybrid constructions of CFRP with aluminum or titanium materials provide high strength in compression and tension at low weight. However, drilling holes in these combined materials for bolts and fasteners is difficult as these are very dissimilar materials. In drilling these combined materials tool wear is high and hole quality is poor. New tool materials are needed to drill these two materials together. Coated tools have improved surface hardness and wear resistance and may provide a suitable material for drilling of CFRP-Ti stacks. In this study an uncoated carbide drill and diamond, BAM, Nanocomposite and AlTiN coated carbide drills were investigated in drilling CFRP only, titanium only and CFRP-Ti stacks. Changes and mechanisms were investigated in drilling tool wear. Changes in hole quality were observed with various coatings as tool wear increased. In drilling CFRP only diamond coating showed the lowest tool wear and superior hole quality to other coated drills. Cutting edge rounding by abrasion was found to be the principle wear pattern. Hole size was found to influenced by tool wear as the coating surface was removed by abrasion. In drilling titanium only catastrophic chipping of the cutting ege was observed near the chisel edge. This occurred during in the early stages of tool use and became less severe with a higher hole number. Holes were slightly oversized in drilling titanium with no trend of increasing or decreasing. Burr height was not observed to increase with the exception of BAM coating. In drilling CFRP-Ti stacks, abrasion from CFRP was found to be the dominant wear mechanism. Catastrophic chipping was not observed in stacks as drilling in CFRP removed the titanium adhesion layer. In stacks both CFRP and titanium holes were found to be oversized and increase in diameter with hole number.
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Details
- Title
- Drilling of carbon fiber reinforced plastics/titanium stacks with ultra hard coated carbide tools
- Creators
- Caleb Mark Sturtevant
- Contributors
- Dave Kim (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525284601842
- Language
- English
- Resource Type
- Thesis